Solidification techniques for low softening point petroleum pitch

ABSTRACT

This alternative fuel is a reclaimed waste product which has a solid, particulate consistency at ambient temperature. The fuel comprises a composite of petroleum pitch and a powder coating. The powder coating penetrates into the surface of the pitch. The powder coating is recycled ash, pulverized coal, or pulverized petroleum coke.

CROSS REFERENCE TO RELATED APPLICATION

The present patent application is based upon and claims the benefit of provisional patent application No. 62/749,263 filed on Oct. 23, 2018.

TECHNICAL FIELD

This invention relates to using petroleum pitch as a fuel. More specifically, the invention relates to a composite of petroleum pitch and a powder coating end a method for producing the composite.

BACKGROUND OF THE INVENTION

The industry has a long-standing need to expand the use of lower softening point petroleum pitch. Solidification of the pitch is not necessarily the issue. In fact, soft pitch will solidify on its own. Rather, the problem is keeping the pitch from clumping together, balling up, or sticking to itself. The desired purpose is to be able to use the pitch as a fuel source. Coal fired power facilities, in particular, could benefit from using the composite of this invention.

SUMMARY OF THE INVENTION

This invention includes a number of different embodiments for using powder coatings to prevent pitch from sticking and clumping. One embodiment adds the powder coating during the cooling phase of pitch solidification. This allows the powder coating to penetrate more deeply into the pitch. The reclaimed waste product has a solid, particulate consistency at ambient temperature comprising a composite of petroleum pitch and a powder coating. The pitch is lower softening point petroleum pitch. More specifically, the pitch is solvent deasphalted (SDA) petroleum pitch. The powder coating is recycled ash, pulverized coal, or pulverized petroleum coke.

One embodiment uses powdered coal or ash from the coal burning industry. Ash is produced when coal is burned. Approximately 20% of coal falls out as ash when burned. This ash must be disposed of properly. By taking this ash and adding it to petroleum pitch, one does not produce more net ash. The reclaimed ash simply falls back out when the pitch is burned. The pitch itself produces little to no ash at all.

Powdered coal is the preferred coating for pitch because it will penetrate the surface of the pitch and pre-ignite in the combustion chamber of the power plant. This will help with better combustion and more complete burning of the pitch. This is done by increasing the surface area of the pitch to initiate combustion and enhance better burn of the fuel. Ash would not have the same effect, however there are some benefits to ash in that it is a waste product of the coal industry.

DETAILED DESCRIPTION OF THE INVENTION

The following details various embodiments of the invention.

The invention will allow penetration into the coal fired power sector fuel market by providing a way to solidify solvent deasphalted (SDA) pitch and prevent clumping for improved performance. Recycled waste ash, pulverized coal, or petroleum coke is used as a penetrating dust coating. In a preferred embodiment, the powder coating is coal ash. As previously discussed, the powder coating penetrates the surface of the pitch. Preferably, the product is fuel in the form of a pastille. Alternative forms of the product can be briquets or flakes. The powder coating, when applied early within the cooling step of the pitch, will partially penetrate the surface of a pastille. Once fully solidified, the low melt point SDA pitch fuel will ship as a solid without significant dusting, melting or conglomerating within truck, rail, or barge equipment.

The product is used as a fungible coal additive within coal handling equipment such as hoppers, conveyers, and pulverizers. The invention will reduce ash generation within the coat fired power sector. For an equivalent heat demand, the use of recycled ash, sourced from the power plant itself with the pitch, will produce less total ash when using SDA pitch as a coal additive. The use of a penetrated ash coating will prevent gumming of the petroleum pitch during the pulverizing, preheat, and fuel eduction steps.

The invention will provide flame stabilization via early ignition when the SDA pitch is coated with pulverized coal. The use of penetrated coal powder will also prevent gumming of petroleum pitch during pulverizing, preheat, and fuel eduction steps. Additionally, the coal coating will provide increased surface area for the SDA pitch which will increase the ignition surface area for a higher Btu content solidified SDA pitch. The fuel will then burn earlier and hotter thus stabilizing the flame and provide more thorough combustion of the coal fuel balance. The use of a powder coating to solve dusting, melting, and conglomerating issues associated with logistics will avoid an alternate logistics solution which would require an increase to the SDA pitch softening point. This use of powder coating decreases the deasphalted oil (DOA) quality within the SDA Unit and avoids the financial penalties within downstream hydrotreating and FCC Units. DOA is the primary product generated in the SDA Unit and its physical properties are tightly controlled to avoid contaminants.

These embodiments enhance the ability to provide additional outlets for petroleum pitch via a new solidification process and will open opportunities for low CAPEX bottom of the barrel upgrading. With the new International Marine Organization rules, costs associated with low sulfur cutter stocks such as ULSD are expected to increase and high sulfur pitch/asphalt/VTBs prices are expected to decrease. Removing sulfur from SDA pitch is not economically feasible without installation of high CAPEX, traditional refining techniques such as delayed coking. A lower CAPEX, faster installation option for bottoms upgrading is provided with SDA/ROSE technologies. Providing an outlet market for pitch will enable smaller refineries which cannot hurdle the economies of scale associated with coker CAPEX providing an alternative option to produce high quality DAO feed for FCC/Hydrocracker units via low CAPEX SDA/ROSE installations.

The advantages of this invention are noted. Currently any issues associated with melting and conglomeration of petroleum pitch is handled by producing a higher softening point product. This in turn produces lower quality DAO. By using penetrated powder coating, the logistical issues are resolved, and low melt point SDA pitch can continue to be produced Without downgrading DAO quality. Also, by solidifying into 2×4 mm pastilles versus larger briquet type product, the fuel will have a shorter residence time within the power plant's pulverizers, thus reducing potential melt and conglomeration risk. The solidified pitch is also superior with a 35% higher Btu content, lower ash content, and lower mercury content when compared to coal Once the solidified fuel market is developed, bottom of the barrel upgrading options for low CAPEX SDA/ROSE installations will be very competitive versus delated coker applications.

The above detailed description of the present invention is given for explanatory purposes. It will be apparent to those skilled in the art that numerous changes and modifications can be made without departing from the scope of the invention. Accordingly, the whole of the foregoing description is to be construed in an illustrative and not a limitative sense, the scope of the invention being defined solely by the appended claims. 

I claim:
 1. A reclaimed waste product which has a solid, particulate consistency at ambient temperature comprising a composite of petroleum pitch and a powder coating.
 2. The product of claim 1 wherein the pitch is lower softening point petroleum pitch.
 3. The product of claim 1 wherein the pitch is solvent deasphalted (SDA) petroleum pitch.
 4. The product of claim 1 wherein the powder coating is pulverized coal.
 5. The product of claim 1 wherein the powder coating is recycled coal ash.
 6. The product of claim 1 wherein the powder coating penetrates the surface of the pitch.
 7. The product of claim 1 wherein the product is fuel.
 8. The product of claim 1 wherein the product is in the form of pastilles.
 9. The product of claim 1 wherein the product is in the form of briquets.
 10. A method for producing a reclaimed waste product which has a solid, particulate consistency at ambient temperature comprising the steps of: cooling petroleum pitch; coating the cooling pitch with a powder coating during the step of cooling; and allowing the powder coating to penetrate more deeply into the pitch during the step of cooling.
 11. The method of claim 10 wherein the pitch is lower softening point petroleum pitch.
 12. The method of claim 10 wherein the pitch is solvent deasphalted (SDA) petroleum pitch.
 13. The method of claim 10 wherein the powder coating is pulverized coal.
 14. The method of claim 10 wherein the powder coating is recycled coal ash.
 15. The method of claim 10 wherein the powder coating penetrates the surface of the pitch. 